Found the answer ****
The question was: When there is a cross walk are we restricted in using US only and therefore cannot bill another type of image guidance?
Response: The parenthetical notation on CPT 55700 to use 76942 for 55700 is not valid when using a different modality, such as MRI, for the image guidance for the biopsy. As we know, CMS and AMA CPT are not always in agreement. For your example of using MRI guidance for 55700, use CPT 77021, “Magnetic resonance guidance for needle placement (e.g. for biopsy).” Since the modality is more complex than ultrasound and it would be a misrepresentation of the service performed to use the lesser ultrasound code 76942.
the following additional information to be helpful: The reporting of imaging guidance is one area where CMS has given instructions that conflict with the guidelines published by the American Medical Association (AMA). Imaging guidance can be performed with fluoroscopy (77002), ultrasound (76942), computed tomography (CT) (77012), and magnetic resonance imaging (MRI) (77021). The CMS and the AMA both agree that when multiple modalities are utilized to guide a biopsy procedure, only the most complex (highest cost) imaging guidance procedure may be reported. The hierarchy, from most complex to least complex, is: MRI, CT, ultrasound, and then fluoroscopy. There are National Correct Coding Initiative (NCCI) edits that prohibit billing these codes together on the same date of service.
Where the AMA and CMS conflict, is regarding the number of times an imaging guidance procedure can be reported. The AMA has always recommended it is per discrete lesion biopsied. CMS has restricted this reporting to only once per session. Per the National Correct Coding Initiative Policy Manual for Medicare Services, Chapter IX:
CPT codes 76942, 77002, 77003, 77012, and 77021 describe radiologic guidance for needle placement by different modalities. CMS payment policy allows one unit of service for any of these codes at a single patient encounter regardless of the number of needle placements performed. The unit of service for these codes is the patient encounter, not number of lesions, number of aspirations, number of biopsies, number of injections, or number of localizations.
CMS has made it very clear that these codes may not be reported more than one time. CMS rules always over-rule AMA instructions, so the imaging guidance codes should only be reported once per patient encounter. If, in the rare occurrence, the patient has more than one encounter on a day and imaging guidance is performed during both encounters, a -59 modifier should be appended to one of the guidance procedures. If the same modality of guidance is utilized (e.g., ultrasound guidance used for both occurrences) it doesn't matter which instance of the code is appended with the -59 modifier. If two different types of guidance are utilized at the two sessions, the -59 modifier should be appended to the imaging guidance procedure of lowest complexity as defined above.